The Mars Express mission of the European Space Agency has released new processed images of Huygens crater on the southern hemisphere of Mars. The huge crater, taking up the whole bottom edge of the photo (see the scalebar at the top!), is about 1 bilion years old and has been partially filled with sediments. Check out the darker "dendrites" feeding into the secondary craters! These look just like desert drainages.
Many more images, including rotated and profile views, are here . Fantastic!